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本文应用土壤物理学的基本原理,根据两年定位观测的土壤水文资料,对陇东黄土高原沟壑区人工刺槐林地土壤的导水性进行了较为系统的分析和研究。在实验中应用土壤水分再分布法,实测了地表的入渗能力和土体内部的非饱和导水能力。模型选择结果表明,该地区土壤的入渗过程符合菲利普(Philip)方程: i(t)=1/2St~(-1/2)+A 所表示的入渗规律。为了判断实际降雨时地表的入渗情况,确定了S值和积水前时间t_P的计算方法。根据霍顿(Horton)产流理论,用微机模拟计算了不同雨型下的入渗过程。土体内部的导水性可以由土壤导水率K(θ)来表示,而K(θ)又完全可以由土壤水分再分布参数a、b反映出来。拟合结果表明,θ与a、b(θ=at~b)的相关系数在各测点上均在0.9以上。最后,应用典型相关法分析了土壤导水性与各环境因子之间的关系。分析结果证明,林龄较大的林分对土壤的导水能力有较强的改善作用,而林龄较小的林分的这种作用很弱。同时,这种作用的强弱与林分配置的地貌部位有密切的关系。
Based on the basic principles of soil physics and based on the two-year positioning and observation of soil hydrological data, the paper conducted a systematic analysis and study on the soil water conductivity of Artificial Robinia pseudoacacia in Gansu Loess Plateau. In the experiment, the soil moisture redistribution method was used to measure the infiltration capacity of the ground and the unsaturated hydraulic conductivity within the soil. The result of model selection shows that the infiltration process of soil in this area accords with the infiltration law represented by Philip equation: i (t) = 1 / 2St -1 (1/2) + A. In order to judge the infiltration of surface during the actual rainfall, the calculation method of S value and t_P before stagnant water was determined. According to the Horton runoff theory, the infiltration process under different rainfall types was calculated by computer simulation. Soil water conductivity can be expressed by soil water conductivity K (θ), and K (θ) can be completely reflected by soil moisture redistribution parameters a, b. The fitting results show that the correlation coefficient between θ and a, b (θ = at ~ b) is above 0.9 at each measuring point. Finally, the relationship between soil water conductivity and environmental factors was analyzed by canonical correlation method. The results of the analysis show that the older stands have a better effect on the water conductivity of the soil, while the younger stands have a weaker effect. At the same time, the strength and weakness of this role are closely related to the topography of the site.